1. Field of the Invention
This invention relates generally to a device holder for WDMs, and more particularly to a device holder for retaining WDMs in an optical module.
2. Description of the Related Art
WDM systems are widely deployed in modem communications networks. In a WDM system, multiple channels are carried over a single optical fiber without interference between the channels, so that channel-carrying capacity is increased. A WDM system includes a WDM module that secures a plurality of WDMs therein. WDMs must be properly secured in the WDM module, to ensure their reliable and durable operation. Various means have been developed for securing WDMs.
Conventionally, the WDM module is fixed to the optical module by epoxy resin. However, epoxy resin takes a long time to solidify (generally 2 or 3 hours at a temperature of 110 degrees). Additionally, epoxy resin tends to degrade and lose strength after repeated changes in environmental conditions.
Furthermore, WDM modules are usually made of metal, which transfer heat very fast. We know that temperature can adversely affect the optical performance of a device, including the stability of the device.
It is desired to provide an improved device holder that is capable of effectively and reliably securing WDMs in an optical module.
An example of a device holder is disclosed in a co-pending patent application, U.S. Ser. No. 10/012005, filed on Nov. 30, 2001 by the same inventor, which is hereby incorporated by reference.
An object of the present invention is to provide a device holder for WDMs which can be firmly fixed to an optical module.
Another object of the present invention is to provide a device holder, which is made of a material which can help maintain a normal operating temperature of the WDMs mounted in an optical module.
In order to achieve the above objects, a device holder according to the present invention comprises a mounting substrate, a plurality of protrusions extending upwardly from the substrate, two side mounting beams and a middle mounting beam. Adjacent protrusions form grooves therebetween for retaining the WDMs therein. The device holder is mounted to a bottom of an optical module box using screws. The device holder is injection molded and is made of a specific thermoplastic material.
Other objects, advantages and novel features of the present invention will be drawn from the following detailed description of a preferred embodiment of the present invention with attached drawings, in which: